This invention pertains to engine driven welding machines, and more particularly to tanks that hold fuel for welding machine engines.
A vital part of every engine driven welding machine is the tank that holds the fuel for the engine. In prior engine driven welding machines, the fuel tank was located entirely within the base of the machine. A filler hole was provided in a top wall of the tank. A suitable cap removably closed the filler hole. By removing the cap, a fuel nozzle could be inserted into the tank through the filler hole.
Although the prior fuel tanks served their intended purpose, they possessed certain disadvantages. For example, the top wall of the tank, and thus the filler hole, was at a low height on the welding machine, often only several inches above the floor. Consequently, a person filling the fuel tank was required to bend over to insert the fuel nozzle into the filler hole. A related drawback was that there was very little warning given to the person that the tank was approaching a full condition. As soon as the tank was filled up to the top wall, which was difficult to observe, any additional fuel would spill out the filler hole. The spilled fuel would run down the sides of the fuel tank and into the welding machine base, where it was impractical to wipe up. Fill gauges were often incorporated into the fuel tanks, but they were not sufficiently sensitive to indicate a full tank condition quickly enough to prevent spillover. Also, the filler hole was on one side of the welding machine, so that side of the machine could not be placed against a wall.
In some applications, fuel tanks have been rendered more convenient to fill by making them with long filler tubes and by locating the filler tube opening so as to be easily accessible. A long filler tube has the additional advantage of providing a storage space for excess fuel that is delivered after the tank is full but before the fuel delivery pump is stopped, provided there were no leaks in the filler tube or in the junction between the filler tube and the tank. However, a long filler tube presents the potential problem of a buildup of air pressure within the tank during rapid filling. If the filling is suddenly stopped, the air pressure can force any fuel in the filler tube back up and out its openings, thereby spilling fuel and possibly even spraying it on the person filling the tank. The reduced diameter of the filler tube also created a high velocity of fuel moving up the tube during filling that could easily spill if not shut off in time.
It is known to provide engine driven welding machines with fuel tanks having long filler tubes. However, the tops of the prior filler tubes and their caps were exposed above the top of the welding machine cover.
U.S. Pat. Nos. 4,759,458 and 5,320,147 and German patent 23 53 448 show filler tubes that have enlargements near their respective openings. The enlargements serve as chambers for temporarily storing fuel that is forced back out the filler tubes by air pressure inside the fuel tank. The arrangement of U.S. Pat. No. 4,759,458 also includes lines that vent air in the tank to the filler tube chamber.
Although the designs of some prior fuel tanks possess certain desirable characteristics, there nevertheless is room for further advancements in fuel tank design.
In accordance with the present invention, a fuel tank filler assembly for engine driven welders is provided that combines anti-splashback with protective and aesthetic features. This is accomplished by apparatus that includes a grommet that fits in a welding machine cover and over a fuel tank filler tube a short distance above an expansion space in the filler tube.
The grommet has a bent side wall, which may be U-shaped, with top, bottom, and front edges. The space between the side wall is closed along its bottom edge with a bottom wall. The side wall front and top edges are turned outwardly to form flanges. The edge of the bottom wall not surrounded by the side wall has a downturned flange. The grommet bottom wall has a hole through it that is defined by a flexible lip.
The fuel tank filler tube has a lower end that opens into a reservoir, with the filler tube and the reservoir being made of one piece of polymeric material. The reservoir fits neatly within the welding machine base. An upper end of the filler tube is approximately at waist height to a person. The filler tube has a variable cross section and is configured to clear various components inside the welding machine. The top cover on the welding machine is cut out over the filler tube upper end.
The grommet is attached to the welding machine top cover so as to fit within the cutout therein. When the grommet is in place, its flanges overlie the welding machine top cover, but its bottom wall is located below the machine top cover. The hole in the grommet bottom wall fits over a circular top portion of the fuel tank filler tube. The outer diameter of the filler tube top portion is slightly larger than the inner diameter of the lip of the grommet hole. Consequently, the grommet lip bends slightly as the grommet is fit over the filler tube, thereby creating a tight seal between the filler tube and the grommet. The filler tube upper end and its cap are below the machine top cover.
The filler tube expansion space is below the grommet bottom wall. The expansion space protrudes from one side of the filler tube. The cross sectional area of the expansion space is greater than the area of the filler tube immediately below the expansion space. Accordingly, any potential splashback of the fuel up and out the filler tube during fuel delivery is prevented, because the fuel can temporarily accumulate in the expansion space. Similarly, the decreased velocity of the fuel rising in the filler tube when it reaches the expansion space gives the automatic fuel shut off valve sufficient time to react and stop the fuel flow, thus preventing spillover.
Further in accordance with the present invention, the combined functional and aesthetic features of the welding machine include its exhaust system. The exhaust system is designed such that the engine muffler is a short distance below the welding machine top cover. A muffler exhaust tube rises vertically out of the muffler. There is a hole through the top cover aligned with the muffler exhaust tube. A bent tail pipe is clamped to the muffler exhaust tube and protrudes through the hole in the top cover. By loosening the clamp, the tail pipe can be rotated 360 degrees about the muffler exhaust tube and then reclamped at any desired angular position. In that manner, a person can direct the exhaust gases from the engine in any desired direction.
The method and apparatus of the invention, using an expansion space on a filler tube that is protected at its upper end, thus enables a welding machine fuel tank to be filled with convenience and safety. Any fuel that does spill out of the filler tube is prevented by the grommet from running inside the machine.
Other advantages, benefits, and features of the present invention will become apparent to those skilled in the art upon reading the detailed description of the invention.